Conventionally, a washer fluid heating device has been mounted on a vehicle, etc. to remove frost in winter. For example, Patent Literature 1 describes a washer fluid heating device having a structure in which a heating chamber is accommodated in a heat-retaining hot water storage chamber and an electric heater is accommodated inside the heating chamber. In the heating device described in Patent Literature 1, a washer fluid of the heat-retaining hot water storage chamber may be allowed to flow into the heating chamber by opening an outflow passage of the washer fluid at an upper part of the heating chamber. After the washer fluid is heated by the electric heater inside the heating chamber, the washer fluid is supplied to a washer nozzle by driving of a washer pump and sprayed from the washer nozzle.